Poly(glycerol sebacate) (PGS) is a cross-linkable elastomer formed as a co-polymer from glycerol and sebacic acid. PGS is biocompatible and biodegradable, reduces inflammation, improves healing, and has antimicrobial properties, all of which make it useful as a biomaterial in the biomedical field.
To create a PGS thermoset/solid structure, neat PGS resin must be crosslinked/cured at elevated temperatures. However, at physiological temperatures, PGS resin is a liquid and flows, thus limiting the application of neat PGS resin. Therefore, it is generally required to cast the PGS resin in a mold to hold the PGS resin shape during the crosslinking step at an elevated temperature to create a shaped thermoset structure.
As a result, creating any kind of spherical conformations of PGS is especially difficult, even more so when microparticles or microspheres are the intended article. PGS microparticles may be created from neat PGS resin through emulsion and solvent evaporation, but subsequent thermal processing steps to cure the PGS microparticles result in melting the PGS microparticles and a loss of their spherical conformation.
Other methods of making crosslinked PGS structures involve the use of a dissolvable solid form, addition of fillers to “solidify” the resin, or changing the chemistry of PGS to allow for crosslinking methods other than thermal curing.
U.S. Pub. No. 2009/0011486 describes nano/microparticles formed from poly(glycerol sebacate acrylate) (PGSA). However, this involves incorporating photo-crosslinkers into PGSA and ultraviolet (UV)-curing the PGSA microparticles to form solid particles. UV photoinitiators and catalytic crosslink agents are known to elicit immune responses to both the toxicity and by-products of use, making such particles unfavorable for use in biological systems.